> On the Periodic Table of Elements, which element is represented by the letter K?And the answer: potassium.Photo credit: public domain.On the periodic table, potassium is represented bythe letter K, because its Neo-Latin name is kalium. Potassium is very importantto plants and animals, as plants need it for photosynthesis, and it helps animalmuscles work, including the muscles that control the heartbeat and breathing.The periodic table is an exhibition of human genius. Dmitri Mendeleev, aRussian-born scientist of the 1800s, invented not just a means of organizing theEarth's elements, but created a template that would go so far as to predict those which had not yet been discovered. During his studies of chemistry, Mendeleev worked as a student in majorlaboratories, working with every element he could get his hands on. With thishands-on knowledge of the field, he then looked to categorization. At the timethe 60 known elements were sorted according to atomic weight. However, Mendeleevsoon realized that the most significant relationships between elements hadlittle to do with their respective atomic weights: the relationship betweenweights was periodic. At the beginning of the list of elements, characteristics repeat every sevenelements (it was later determined that they repeat every eight elements, but inthe 1860s the noble gases had not yet been discovered). As the masses of theelements increased, the pattern of repetition continued, but, as Mendeleevdiscovered, the pattern began to get fuzzier the farther down on the table hewent. This puzzled the scientist. How could he make sense of deviations from a patternif half of it fit perfectly? Then, a realization: the numbers weren't workingnot because the ideas were wrong, but because some elements simply hadn't yetbeen discovered. As such, Mendeleev inserted gaps into the periodic table, and the elements fellperfectly into place. Seven element periods for the first two rows, and 18element periods for the next two. Mendeleev was so certain that he went so faras to predict the properties of the missing elements!Since his discovery, the periodic table has made its way into nearly everychemistry lab in the world. Learn more about the groupings and usage of theperiodic table here [https://www.youtube.com/watch?v=P6DMEgE8CK8].